Simply start by hand, then wrench the nut into position anywhere along the stud or fastener-the expansion of the top slotted section locks the nut. Made from a single piece of metal, these nuts have greater fatigue strengths than similar size nylock nuts and can be used in higher temperature applications; low profile jam nut. ASME B1.1 Class 3B thread requirement. Cadmium plating provides excellent corrosion resistance and improves conductivity.